“Quite a brilliant chap, oddly enough. We were in the same year at Cambridge. I never dreamed then that we’d wind up by being fellow shopkeepers. However...” Payne eyed his wine quizzically and scratched a fragment of dried toothpaste from the glass rim with his nail. “It seems he was rather unkind to the oaf Biggadyke—absolutely deservedly—about a month ago. Hence, I think, the reprisal on the eye. He was very fond, of it, poor chap,” Payne added sadly.
Purbright blocked with a pawn the line of threatened advance by Payne’s queen, and went on: “The question that no one seems able to settle is where Biggadyke obtained his explosive. It looks as though I shall have to go back without an answer.”
Payne looked up. “So that’s why they sent you, is it? I was wondering if you were M.I.5 or something. Kebble’s convinced of it.”
Purbright grinned. “That’s probably because I took your advice and was shockingly indiscreet. Tell me, though, from what you know of Biggadyke how do you imagine he’d set about that queer campaign of his? Where would he get the stuff?”
Payne considered. “As a haulage contractor he made some useful, if questionable, contacts during the war, I believe. Perhaps there’s a black market in gelignite, or something.”
“There is, unquestionably. But I should suppose that quotas are pretty well taken up by gentlemen with banking interests. I’d be most surprised to learn that Mr Biggadyke had been able to whistle any his way. Anything else occur to you?”
Payne poured out some more wine before replying. “There was a rumour,” he said slowly, “of some explosive having disappeared from that Home Guard place...”
“Civil Defence,” Purbright corrected.
“Yes, but that’s at Flaxborough anyway. You’ll know all about it.”
“Not all, no. But the connection with this lot seems very tenuous.”
Purbright returned his attention to the game. Payne’s last move, he noticed, appeared to have no immediate object. But his own interest had waned and he contented himself with advancing another pawn. After quite a long silence he asked: “Would it be possible, do you think, for Biggadyke to have manufactured his explosive himself?”
Payne hesitated. “Chemically, you mean?”
“Yes. Say it were some nitro compound. Nitro...well, nitro-glycerin: I suppose that’s the best known.”
Payne thoughtfully caressed the waxed points of his moustache, then shrugged. “Feasible, I imagine. Very dangerous, though.” He got up and crossed the room to a bookcase. “There may be something among these that will help. They’re a little out of date as textbooks go but organic chemistry is less subject to fashion than physics.”
Purbright watched him kneel and pull out, one by one, the books on the bottom shelf. The lettering on the spines of most of them was nearly indiscernible; they probably had been second-hand when Payne acquired them in his university days.
At last Payne found the volume he had been seeking. He reached up and put it on the top of the case between a pair of photographs while he tidied the rest of the row. Purbright glanced idly at the two pictures. One was a faded sepia portrait of a woman in late Victorian or Edwardian dress; the other was of a small girl standing beside a television camera.
Payne brought the book over, referred to its index and thumbed back to the section he wanted.
“Simple enough in theory,” he said after a while. “Allow a mixture of concentrated nitric and sulphuric acids to act on ordinary glycerin and separate the oily liquid that rises. There you have it—nitro-glycerin.”
“Well, then: even Biggadyke...”
Payne shook his head. “No, I said it was simple in theory. But the stuff is deperately unstable, remember. You can’t carry it around like lemonade. One good jolt and—whoosh!”
“Yet dynamite is safe enough to handle, surely. Isn’t that nitro-glycerin in some form or other?”
Payne turned a page. “It is, actually. Hang on a minute.” He read further through the text. “Yes, here we are: they absorb the liquid nitro-glycerin in something called kieselguhr.”
“And what’s that?”
“No idea. Here it just calls it ‘an inert, clay-like substance’.”
Purbright, feeling somewhat inert himself, said nothing for a few moments. Payne closed the book and waited.
“Detonators,” Purbright said suddenly. “All these timebomb things are set off by detonators, aren’t they?”
“Yes, I suppose they are.” Payne frowned at the cover of the textbook. “I don’t think this would be any use,” he said. “You’re still thinking along do-it-yourself lines, are you?”
“More or less.”
“Well, the only detonating agent I can call to mind is mercury fulminate. I don’t know whether it’s still used nowadays.”
“It could be made at home, though? Or something like it?”
“I wouldn’t like to say offhand.”
Purbright stretched, yawning. “Never mind,” he said, “it all sounds terribly unlikely. Anyway, from what I’ve heard of Biggadyke I can’t picture him tackling anything so complicated.”
Payne smiled gently and began to pour more wine. “We all have our unsuspected talents,” he observed.
The next morning, Purbright caught an early train to Flaxborough in order to report upon his perplexities to the county chief constable.
Mr Hessledine’s manner was courteous but clinical. He had, he said, studied already a verbatim report of the inquest. The affair had been closed to the coroner’s satisfaction, certainly, but the essential question of the source of that impossible fellow’s explosive had not even been touched upon. One of his officers was under a cloud, and he trusted that Mr Purbright had produced evidence sufficient either to eliminate Chief Inspector Larch—which was much to be desired—or to prove his complicity. Now then, what had Mr Purbright to say?
Mr Purbright confessed unhappily that he was in no position to relieve the Chief Constable of his doubts one way or the other. He had been unable to resolve the ominous coincidence of the explosions and the theft from the Civil Defence store. Worse, far worse, his inquiries had revealed a relationship between Biggadyke and the chief inspector that was at once paradoxical and pregnant with possibilities that did not exclude murder itself.
Hessledine listened impassively to the account of Larch’s friendship with Biggadyke; of the local rumours of their collusion; and of the seduction of Hilda Larch.
When he had finished, he looked apologetically at the Chief Constable and said: “I don’t seem to have made matters any easier, do I, sir?”
Hassledine gave him a magnanimous smile. “You’ve been very thorough, Mr Purbright. I’m only sorry that you found yourself placed in such invidious circumstances. Of course, I had no idea that...” He blinked and left the sentence unfinished.
“Quite so, sir.”
Hessledine rose from his desk and walked gracefully to the window. “The proper thing to do now,” he said to his reflection in its panes, “would be to suspend Mr Larch from duty until some sort of an official inquiry could be made. But you see the difficulty, don’t you?” He half turned in Purbright’s direction.